The Master Lock Magnum M175LFEC2 Heavy Duty Outdoor Combination Locks features a 2in (51mm) wide zinc body for strength and reliability. The 3/8in (10mm) diameter octagonal shackle is 1-1/2in (38mm) long and made of Tough-Cut boron-carbide, 50% harder than hardened steel, offering maximum resistance to cutting and sawing. The roller pin cylinder provides maximum pick and pry resistance. The hinged dial cover and shackle seal offers superior weather protection, and reinforced body bumper protects against scratches. Includes two set your own combination locks, without the need for a reset tool. The Lifetime Guarantee provides peace of mind from a brand you know and can trust.